Karen Cawston

1996 Research

Abstract: Documentation of Tentacle and Neural Regeneration of Two Land SlugsMentor: Stacia B. Moffett, PhD, WSU Department of Zoology

The neural regeneration of surgically removed tentacles of two land slugs, Arion ater and Limax maximus, was studied. Much documentation presently exists chronicling the regeneration ability of the gastropods. This ability for neural regeneration appears to be founded in gastropod evolutionary survival. Human neural regeneration occurs, but of a far more limited nature. In attempt to advance the understanding of human neural regeneration, the identification of the blood factors present during gastropod regeneration, as well as the sources and pathways involved, has been studied. To help document the presence of new neurons, bromodeoxyuridine (BrdU), which attaches to the nuclei of dividing cells, was injected into the animals. Primary and secondary antibodies were attached to the BrdU, with the secondary antibody having a fluorochrome marker conjugated to the antibody cells. This marker was visible under the fluorescent microscope. With such DNA marking, newly dividing cells, including neurons, become visible. To further document the process of neural regeneration, bioassay was also used. During cell growth, both stimulatory and inhibitory factors are present to control the growth process. The blood of the animals was added to mouse mammary cancer cells to identify either an inhibitory of stimulatory effect on the cancer cells. The bioassay further identifies characteristics of the molecules responsible for the effect and compares these to other molecules with similar attributes. The study of the regeneration of the nervous system of these animals is highly accessible, yet the chemical and molecular clues are shared with humans. Therefore, understanding how the process of neural regeneration occurs in the pulmonates enhances the study of nervous system regeneration in humans.